Aluminosilicate sab-15 as an additive for reducing the toxic and carcinogenic compounds present in tobacco smoke

ABSTRACT

The invention relates to the use of the aluminosilicate SAB-15, or the acidic or sodic forms thereof, interchanged with Fe, Na, K, Ca, Ce, Zr, the oxides of Fe, Na, K, Ca, Ce, Zr, and mixtures of same as an additive for reducing the toxic and carcinogenic substances present in tobacco smoke.

FIELD OF THE INVENTION

The present invention relates to the use of aluminosilicates,particularly SAB-15, as an additive for reducing the toxic andcarcinogenic compounds present in tobacco smoke.

STATE OF THE ART

The habit of smoking tobacco has been and is a global problem with verynegative consequences on human health. Its impact on the departments orministries of public health is of great importance. More than 4000different compounds have been identified in tobacco and in the smokegenerated when burning same [R. R. Baker, Progress in Energy andCombustion Science, 32 (2006), 373], among which at least 60 arerecognized as toxic and carcinogenic. These compounds include tars,carbon monoxide and dioxide, acetaldehyde, phenols, acetone,formaldehyde, benzene, toluene and nicotine. Nicotine is the mainaddictive component present in tobacco, and in the human body it isconverted into a metabolite called cotinine and is used as a referenceindex for measuring the degree of exposure to tobacco smoke.

The process of smoking a cigarette generates the occurrence of two typesof smoke streams, the so-called mainstream and sidestream. Themainstream corresponds to smoke which is generated when burning thetobacco and goes through the cigarette from the lit end to leave throughthe filter end.

Patent document EP2092838 describes the use of certain zeolites andother aluminosilicates and mesoporous solids, in different forms andwith various compositions, adding them and mixing them directly withtobacco in the form of powder, without having to use any type of specialtechnology or adhesive, as tobacco additives for drastically reducingthe amount of toxic and/or carcinogenic compounds that are generatedwhen smoking and are found in the mainstream and sidestream of tobaccosmoke.

Patent application US2005133052 describes the use of mesoporousaluminosilicate molecular sieves modified with aminoalkylsilyl groups infilters for retaining specific compounds.

Patent application US20050133051 proposes the use of filters containingmaterials formed by a porous alumina or aluminosilicate matrixcontaining adsorbent activated carbon and zeolite particles forselectively removing specific compounds from tobacco smoke.

Patent application WO 2004110183 A2 describes filters containing acatalyst dispersed in a porous aluminosilicate matrix, for the purposeof converting the CO in cigarette smoke into CO₂.

Patent application WO 2004086888 describes a filter including at least 2porous monolithic adsorbent segments that are capable of selectivelyremoving components from the smoke stream, and a mixing segment betweenboth.

Patent application CN 102242527 proposes the use of a cigarette papercontaining a microencapsulated adsorbent which allows reducing thecontent of toxic substances in tobacco smoke. The different adsorbentmaterials used include, among others, one or more oxides of Cu, Mn, Zn,Fe, Al, Ti, etc., as well as composite materials where the oxides aresupported by zeolites, MCM-48, or SBA-15.

Zhu et al. [Zhou, F. N. Gu, L. Gao, J. Y. Yang, W. G. Lin, J., Yang,Y.,Wang, J. H. Zhu, Catalysis Today, 166(1), (2011), 39 and Zhou, Gao,Gu, Yang, Yang, Wei, Wang and Zhu, Weinheiman der Bergstrasse, Germany,15(27), (2009), 6748] have described the use of SBA-15 for selectivelyreducing the concentration of tobacco-specific nitrosamines (TSNA) intobacco smoke; however, this article focuses on the synthesis,characterization, adsorption and catalytic activity of SBA-15 andexamines a new pathway which allows increasing the efficiency thereof asadsorbents/catalysts with environmental applications through morphologycontrol.

Patent application WO 2011015861 proposes the use of a filter containingan adsorbent material which is capable of removing phenol from tobaccosmoke. The material is formed by a porous solid (with micro- ormesopores) containing an adsorption promoter which is a hydrophilicorganic proton donor or acceptor substance.

Patent application CN 101433818 claims the use of a mesoporous materialconsisting of SBA-15 for adsorbing particulate matter, tar, phenol andnitrosamines in mainstream tobacco smoke.

Patent applications US2006130855-A1 and US2005133047-A1 explicitlymention the possibility of using SBA-15-based substrates.

The results described in patent document EP0740907 for generating tarsor nicotine when using the acidic and sodium forms of zeolite BETAclearly show the minimum differences with respect to the referencecigarette smoked without an additive.

Different types of equipment that facilitate and can even improveincorporating the additive to fine-cut tobacco, such as for example,speed mixers or orbital mixers, fluidized beds and entrained beds, amongothers, as well as sieves for separating and recirculating the additivethat did not attach onto tobacco fibers, can be used for preparingcigarettes.

BRIEF DESCRIPTION OF THE INVENTION

Therefore in a first aspect, the present invention relates toaluminosilicate SAB-15 or the acidic or sodium forms thereof,interchanged with Fe, Na, K, Ca, Ce, Zr, the oxides of Fe, Na, K, Ca,Ce, Zr and mixtures thereof as an additive for reducing the toxic andcarcinogenic substances present in tobacco smoke, both in mainstream andsidestream tobacco smoke, particularly, toxic substances such as tars,carbon monoxide and nicotine, as well as the components of the liquidsand gases generated when burning tobacco in the smoking process.

In a more particular aspect of the present invention, thealuminosilicate SAB-15 has a spherical morphological shape, tubularmorphological shape or rod shape, or any other shape obtained by varioussynthesis processes and different degrees of acidity obtained byincorporating aluminum in its structure, in a pressurized autoclave thatis under stirring or standing still and under reflux at differenttemperatures, and where it has been interchanged with the cations ofmetals: Fe, Na, K, Ca, Ce, Zr.

In a more particular aspect of the present invention, thealuminosilicate SAB-15 has a pore size comprised between 4-10 nm and amesopore volume preferably greater than 2.2 cm³/g, although the mesoporevolume can be less.

In a second aspect, the present invention relates to a mixturecomprising dry tobacco and aluminosilicate SAB-15, or the acidic orsodium forms thereof, interchanged with Fe, Na, K, Ca, Ce, Zr, theoxides of Fe, Na, K, Ca, Ce, Zr and mixtures thereof as an additive andnot comprising adhesive agents. Dry tobacco refers to a bright tobacco,dark tobacco, fine-cut tobacco, roll-your-own tobacco, pipe tobacco andany other type of tobacco that can be smoked.

In the present invention, agent adhesive refers to compounds with thecapacity to bind or adhere to tobacco or substances incorporatedtherein, for example, guar gum, alginates or other compounds havingsimilar characteristics.

In a more particular aspect of the present invention, the additive is ata concentration comprised between 0.5-10% by weight with respect to thedry tobacco, in another more particular aspect, the additive is at aconcentration comprised between 2-7% by weight with respect to the drytobacco.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the SEM image of a fibrous SBA-15 (A) and a sphericalSBA-15 (B).

FIG. 2 shows the N₂ adsorption isotherms obtained for SBA-15 materialssynthesized in different ways.

DETAILED DESCRIPTION OF EMBODIMENTS AND EXAMPLE EXAMPLE 1 Method forSynthesizing the Different Materials

The SBA-15 was synthesized according to the following method: a pluronicP 123 solution in acidic medium was first prepared to which an amount oftetraethyl orthosilicate (TEOS) was added. The resulting solution wasaged under stirring at 38° C. for 20 hours. It was then transferred toan autoclave with a Teflon liner and kept at 100° C. for 24 hours. Theresulting suspension was washed with water, dried overnight at 100° C.and finally burned at 550° C. for 5 hours (F. Zhang, Y. Yan, H. Yang, Y.Meng, C. Yu, B. Tu, D. Zhao, Journal of Physical Chemistry B.109 (18),(2005), 8723).

The SBA-15_(spherical) was obtained under the following conditions. Anamount of pluronic P 123 was dissolved in HCl. A second suspension withCTABr and water was prepared and added to the first suspension. A smallamount of ethanol was then added, followed by addition of TEOS. Theresulting solution was aged at 35° C. for 45 minutes. It was thentransferred to an autoclave with a Teflon liner at 75° C. for severalhours and finally treated at 105° C. The resulting suspension was washedwith water, dried overnight at 100° C. and finally burned at 550° C.,(A. Katiyar, S. Yadav, P G. Smirniotis, N G. Pinto, Journal ofChromatography A, 1122 (1-2), (2006), 13).

The SBA-15_(reflux) reflux material was obtained under conditionssimilar to SBA-15, but a flask containing the obtained suspensionconnected to a reflux condenser at 100° C. was used in the final step.The resulting solid was washed with water, dried overnight at 100° C.and finally burned at 550° C.

The SBA-15 material at 125° C. was prepared similarly to SBA-15 butmodifying the temperature at which it is kept throughout the finaltemperature of the process, 125° C. instead of 100° C.

The AISBA-15 material was prepared by means of a gel having a molarcomposition: 1 TEOS: 0.02 Al₂O₃: 0.016 P123: 0.46 HCl: 190 H₂O,according to the method described by Vinu A., Hartmann M., Devassy B.M., Halligudi S. B., Bohlmann W., Applied Catalysis A: General, 281,(2005), 207.

The Na-AISBA-15 material was prepared by means of ion exchange from theAISBA-15 material, in which 1 gram of material is stirred for 24 hourswith a 1 M NaCl solution. The resulting material is filtered, washedwith water and dried in an oven at 100° C.

The FeNa-AISBA-15 material was prepared by means of ion exchange fromthe Na-AISBA-15 material, in which in 1 liter of distilled water with1.26 g of Fe(NO₃)9H₂O and 4.5 g of Na-AISBA-15 is added. The resultingsolution is stirred for 24 hours and then filtered, washed with waterand dried in an oven at 100° C.

Table 1 shows the chemical and structural characteristics of some of theadditives that are studied in this application as representativeexamples of such materials, corresponding to SBA-15 samples preparedunder different synthesis conditions or subjected to post-synthesismodifications. FIG. 2 shows the corresponding N₂ adsorption isotherms at77 K.

TABLE 1 Textural properties of some of the additives Na—Al-SBA PROPERTYSBA SBA_(spherical) SBA_(reflux) (autoclave) Pore size (nm)^(a) 6.126.07 6.39 6.14 BET area (m²/g)^(b) 680.5 847.8 1066 915.9 Outer surfacearea 536.3 847.8 668.2 915.9 (m²/g)^(c) Pore volume 0.91 1.06 1.24 0.84(cm³/g)d (^(a)BJH; ^(b)BET method, N₂ adsorption isotherms; ^(c)tmethod, N₂ adsorption isotherms; dmeasured at P/P₀ = 0.995, N₂adsorption isotherms; ^(e)XRF). The nomenclature refers to SBA-15materials prepared with different synthesis conditions or subjected topost-synthesis modifications.

For the purpose of demonstrating the role of the additives proposed inthis invention, the following cigarettes were smoked:

-   a) reference commercial cigarettes 3R4F from the University of    Kentucky and-   b) cigarettes to which the additives were incorporated, using a    smoking machine that worked according to the following operation    variables:

The cigarette smoking conditions and the analysis of the generatedproducts are provided in detail below:

-   -   Fifteen cigarettes were smoked following the specifications of        the ISO 3308 standard (2-second drags, 35 mL inhaled volume,        60-second drag frequency and a drag pressure loss of less than        300 Pa).    -   The cigarettes were conditioned at room temperature and 60%        relative humidity, keeping them in a dryer provided with a        saturated sodium nitrite solution at least for 48 hours before        being smoked.    -   During the smoking process, the smoke, including CO, CO₂ and        other non-condensable products went through the cigarette filter        as well as a trap (glass fiber filter) located before the gas        collection bag. The non-condensable products were collected in a        Tedlar gas bag which was kept for subsequent analysis by gas        chromatography (GC) and the condensable products were collected        in the cigarette filter and in the trap that follows, in which        the condensable products directly inhaled by smokers were        retained.    -   The condensable products retained in the trap located before the        filter were extracted with 2-propanol, assuring that all the        compounds retained in the trap are recovered. The extract is        then dried with sodium sulfate and kept for subsequent analysis        by GC.    -   The CO and CO₂ content in the non-condensable fraction was        determined by GC using a thermal conductivity detector (GC-TCD)        and a CTRI concentric column, which was also used for analyzing        O₂, N₂ and CH₄, in SHIMADZU GC-14A equipment, using calibration        by means of external standards. Quantification was performed by        calculating the response factor (grams of compound/peak area) of        these compounds by means of injecting different volumes (between        0.5 and 2.5 mL) of the corresponding standard (carbon monoxide,        carbon dioxide, hydrogen, methane and oxygen).    -   The analysis conditions were:    -   Carrier gas: He    -   Injector temperature: 28° C.    -   Detector temperature: 110° C.    -   Injected volume: 2.5 mL    -   Constant column flow: 40 mL/min    -   Oven temperature program: isotherm at 110° C.    -   Analysis time 20 minutes    -   The rest of the non-condensable components were analyzed by GC        with a flame ionization detector (GC-FID), using a GAS-PRO        column and the following conditions:    -   Injector temperature: 150° C.    -   Detector temperature: 210° C.    -   Carrier gas: Helium    -   Injected sample volume: 150 μL    -   Constant column flow: 2 mL/min    -   Oven temperature program:        -   Initial column temperature 35° C. for 10 min        -   Heating to 100° C. with a ramp of 5° C./min        -   Heating to 200° C. with a ramp of 15° C./min        -   Final time: 10 minutes    -   The condensable compounds (extracted with 2-propanol from the        cigarette filters and the smoke traps) were analyzed by GC with        a detector using mass spectrometry (GC-MS), using an HP-5MS        column and the following conditions:    -   Injector temperature: 250° C.    -   Carrier gas: Helium    -   Injected sample volume: 1 μL    -   Constant column flow: 2 mL/min    -   Oven temperature program:    -   Initial column temperature 40° C. for 5 min        -   Heating to 320° C. with a ramp of 12° C./min        -   Final Time: 25 minutes

Nicotine standards of different concentrations (between 5 and 300 ppm)were prepared for quantifying the compounds present in the condensedphase of tobacco smoke. They were injected in the equipment and thevalue of the corresponding response factor was obtained from the slopeof the straight line obtained from the graphs representing the amount ofinjected compound vs. peak area. The response factor obtained fornicotine was used for the rest of the analyzed compounds since nicotinewas the main compound. Quantification was carried out in a similarmanner for the gases, in which a mean response factor was used in thecases in which the corresponding response factor was not available.

Cigarette Preparation Conditions

To carry out all the tests, cigarettes in which tobacco fibers weremixed by hand with the catalyst were prepared, aided by a few drops ofethanol. This operation was performed on a sieve which allowedseparating the catalyst that did not adhere to the tobacco, such that apercentage of catalyst was obtained in the nominal mixtures,corresponding to the amount of initially weighed catalyst, and anotherreal percentage, which was that retained by the sample. Agents otherthan ethanol which can be used to aid in the process of mixing thetobacco and catalysts are water, glycerin and other similar compounds,commonly present in tobacco preparations and evaporate with relativeease. Nevertheless, mixing can also be satisfactorily performed withouthaving to use any of these substances.

The characteristics corresponding to some examples which allowillustrating the results that can be achieved with the use of theproposed additives are shown below. The nominal percentage of each typeof additive is indicated. The tobacco used, both in the referencecigarettes and in the different mixtures with the additives, was alwaysthe reference tobacco 3R4F obtained from the University of Kentucky.

Tobacco-Additive Mixtures for the Conducted Tests

A nominal percentage of 4-6% by weight of additive is used in all thecases. The cigarettes were prepared using the method described in“cigarette preparation conditions” and using the additives indicatedbelow. Table 2 shows the mixtures made in the different tests conducted.

TABLE 2 tobacco mixtures Mixtures 3R4F + SBA-15 (4%) 3R4F + SBA-15 (6%)3R4F + SBA-15 (8%) 3R4F + SBA-15_(spherical) 3R4F + Na-SBA-15 3R4F +FeNa-SBA 3R4F + AlSBA-15 (autoclave) 3R4F + Na—AlSBA-15 (autoclave)3R4F + SBA-15_(spherical) (125° C.) 3R4F + SBA-15 (reflux)

Tables 3, 4, 5 and 6 show the results obtained when smoking thecigarettes using the cigarette preparation conditions, the smokingconditions and the conditions for analyzing the generated products andthe examples corresponding to different tobacco-additive mixtures. Thevalues obtained for the following are shown:

-   -   CO and CO₂, in mg of compound/cigarette    -   the amount of some toxic products, in mg of compound/cigarette    -   total particulate matter (TPM) in mg/cigarette, calculated as:

$m_{TTM} = \frac{m_{1} - m_{0}}{q}$

where m₀ is the mass of the trap located before the filter, in mg,before smoking m₁ is the mass of the trap located before the filter, inmg, after smoking a number q of cigarettes.

TABLE 3 CO and CO₂ content in tobacco smoke generated under controlledconditions Sample CO₂ (mg/cigarette) CO (mg/cigarette) 3R4F 40.63 11.223R4F + SBA-15 29.85 10.89 3R4F + SBA-15_(spherical) 31.95 9.02 3R4F +FeNa-SBA-15 37.00 11.45 3R4F + AlSBA-15 (autoclave) 39.69 10.11 3R4F +SBA-15_(spherical) (125° C.) 36.97 9.55

TABLE 4 Number of drags and TPM obtained when smoking tobacco undercontrolled conditions TPM Sample % zeolite Drags mg/cigarette(mg/cigarette) 3R4F 0.0 9 0.76 6.79 3R4F + SBA-15 3.8 9 0.76 2.34 3R4F +SBA-15_(spherical) 6.3 8.5 0.68 3.07 3R4F + FeNa-SBA-15 3.9 9 0.78 2.913R4F + AlSBA-15 5.9 10 0.80 3.21 (autoclave) 3R4F + SBA-15_(spherical)5.8 8.5 0.77 2.44 (125° C.)

TABLE 5 Generation (mg compound/cigarette) of different toxic compoundspresent in the gases collected in the Tedlar bag after smoking tobaccounder controlled conditions Propion- Acet- Sample aldehyde TolueneBenzene aldehyde 3R4F 0.0208 0.0178 0.0849 0.4214 3R4F + SBA-15 0.01520.0135 0.0655 0.2908 3R4F + SBA-15_(spherical) 0.0118 0.0148 0.19441.2061 3R4F + FeNa-SBA-15 0.0203 0.0183 0.0836 0.5511 3R4F + AlSBA-150.0135 0.0101 0.0772 0.6541 (autoclave) 3R4F + SBA-15_(spherical) 0.01280.0099 0.0874 0.4350 (125° C.)

TABLE 6 Generation (mg compound/cigarette) of different toxic compoundspresent in the condensable products retained in the trap located beforethe filter when smoking tobacco under controlled conditions Benz- p-Sample Nicotine aldehyde Phenol Cresol 3R4F 5.93E−01 2.93E−04 4.18E−035.55E−03 3R4F + SBA-15 3.59E−01 1.10E−04 1.98E−04 9.90E−04 3R4F + SBA-2.33E−01 1.75E−04 3.80E−04 2.91E−04 15_(spherical) 3R4F + FeNa- 1.98E−020.00E+00 3.00E−05 1.01E−04 SBA-15 3R4F + AlSBA-15 2.18E−02 0.00E+004.13E−05 1.13E−04 (autoclave) 3R4F + SBA- 2.38E−02 0.00E+00 5.40E−051.38E−04 15_(spherical) (125° C.) Sample Hydroquinone Myosmine Cotinine3R4F 1.03E−02 4.01E−03 5.06E−03 3R4F + SBA-15 4.02E−03 8.90E−04 2.82E−033R4F + SBA- 5.25E−03 1.13E−03 1.56E−03 15_(spherical) 3R4F + FeNa-1.23E−04 1.16E−04 1.81E−04 SBA-15 3R4F + AlSBA-15 2.84E−04 1.43E−041.84E−04 (autoclave) 3R4F + SBA- 3.02E−04 1.43E−04 1.82E−0415_(spherical) (125° C.)

Tables 3 to 6 clearly show that, generally, the proposed additives,mixed with tobacco in the described proportions, provided a significantreduction in the amount of most of the toxic compounds in tobacco smoke.This reduction in turn entailed a decrease of the potential negativeeffects caused by tobacco smoke in smokers and in passive smokers,without causing significant changes in the organoleptic properties,taste and consistency of the tobacco, and without the apparentgeneration of other undesired compounds. On the other hand, not onlywere the toxic compounds reduced, but also the total amount of gases andliquids that are formed when smoking the cigarette (total particulatematter, TPM, plus the liquids retained in the filter) also generallydecreased in a significant manner, whereas solid residue together withash increased. When the process of smoking the cigarette ended, theadditives were retained in the ash or in the tobacco that has not beensmoked.

Table 3 shows the yields obtained for CO and CO₂ when smoking cigarettesprepared with the described mixtures. As can be seen, reductions aregenerally obtained in the amount of CO present in the mainstream tobaccosmoke as a result of the presence of almost all the studied materials.As will be seen below, these reductions are particularly interesting forthe additive referred to as SBA-15 when it is used in nominalproportions of 6 and 8%. The SBA-15_(spherical), SBA-15_(spherical) andSBA-15 at 125° C. materials also provide significant reductions in CO.That is particularly interesting since CO is one of the substancesregulated by laws applicable to commercial cigarettes. The rest of theadditives also provide a reduction, although less, in CO, with the onlyexception of FeNa-SBA-15, which causes a slight increase. It is alsoseen that reductions in CO₂ are obtained in all the studied cases. Itmust be pointed out that the results shown in Table 4 depict asignificant decrease in the total particulate matter (TPM) as a resultof using the proposed additives. These reductions range between amaximum value of 66%, in the case of SBA-15, and a minimum reduction of52% in the worst case, which corresponds to AISBA-15 (autoclave). Thisis also an important feature of these materials since the TPM is closelyrelated to tars that are generated when smoking cigarettes, tars beinganother regulated substance. In fact, the amount of tars is consideredto provide a good measurement of the amount of toxic and harmfulsubstances generated when smoking, all of them considered as a whole. Itcan therefore be concluded that the capacity of these additives forreducing the formation of said toxic substances is very significant.

Table 5 shows, by way of example, the results obtained for theproduction of some toxic and carcinogenic compounds in tobacco smoke. Ascan be seen, all the additives provided a reduction in the formation ofpropionaldehyde with respect to the reference cigarette. Interestingreductions were also observed in the case of toluene, with the onlyexception of the NaFe-SBA-15 material, which caused a slight increase.Similar considerations can be made for benzene and acetaldehyde:reductions are observed for benzene in all cases, except forSBA-15_(spherical) and SBA-15_(spherical) at 125° C., causing a slightincrease. In the case of acetaldehyde, the only additive which causesreductions with respect to the reference cigarette is SBA-15. It cantherefore be concluded that the sample of the SBA-15 material has anexcellent behavior from the viewpoint of applying same as an additivefor reducing the toxicity of the mainstream tobacco smoke since, inaddition to reducing the generation of CO and TPM, it separately reducesall the analyzed toxic compounds.

Table 6 shows the results obtained for other compounds present intobacco smoke in the case of the reference tobacco and with 4 of thestudied additives. The excellent behavior shown by the SBA-15 sample canagain be confirmed, with reductions ranging between 95% for phenol and39% for nicotine. The SBA-15_(spherical) material also caused reductionsin 7 studied compounds, whereas FeNa-SBA-15 caused an increase in all ofsaid compounds, except benzaldehyde.

All the described mixtures can also be prepared by means of using speedmixers, fluidized beds or entrained beds and any other type of equipmentwhich favors mixing the tobacco fiber and additive. Sieves can also beused for separating and recirculating the additive that did not attachonto the tobacco fibers. On the other hand, for other differentconventional cigarette preparations, in which the tobacco-additivemixtures must be prepared manually by smokers themselves, a dispenserproviding the suitable amount of catalyst can be used for preparingbright tobacco, dark tobacco, fine-cut tobacco, roll-your-own tobacco,pipe tobacco and any other product that can be smoked. This dispensercan consist of a blister, in which each cavity contains the selectedamount (between 5 and 70 mg, such that between 0.5 and 7% is obtainedwith respect to the tobacco which will usually be consumed in portionsof about 1 g of tobacco), individual capsules containing said amounts, acontainer including a calibrated or graduated spoon or any anothercalibrated dispenser. To prepare a ready-to-smoke product (MYO, RYO,pipe or other forms), the content of the calibrated dispenser is pouredonto the tobacco fiber and carefully mixed by hand. This method assuresexcellent results which are as good as those shown in Tables 3 to 6.

Tobacco-Additive Mixtures with Different Additive Concentration

The additive used in all the cases was SBA-15. The percentages by weightof catalyst are indicated. The cigarettes were prepared using the methoddescribed in “cigarette preparation conditions” and using nominalconcentrations (percentage by weight) of 4.6 and 8%.

Results Obtained Corresponding to Tobacco-Additive Mixtures withDifferent Additive Concentration

The influence of additive concentration on additive-tobacco mixtures wasalso studied. To that end, mixtures were prepared with a nominalpercentage of catalyst comprised between 4 and 8% using the methoddescribed above. By way of example, Tables 7 and 8 show the resultsobtained when using SBA-15 as an additive. As can be seen, the bestresults were achieved when using the maximum additive concentration,although excellent results, which can be adjusted according to thedesired reduction in toxic compounds, were also obtained in mixtureswith intermediate concentrations.

TABLE 7 Number of drags and TPM obtained when smoking tobacco undercontrolled conditions mg/cigarette TPM Sample % zeolite Drags tobacco(mg/cigarette) 3R4F 0.0 9 0.76 6.79 3R4F + SBA15 (4%) 3.8 9 0.76 2.343R4F + SBA15 (6%) 5.6 9 0.76 1.31 3R4F + SBA15 (8%) 7.3 10 0.76 0.66Sample Hydroquinone Myosmine Cotinine 3R4F 1.03E−02 4.2E−03 6.5E−033R4F + SBA15 (4%) 4.02E−03 8.9E−04 2.8E−03 3R4F + SBA15 (6%) 0.05E+009.5E−04 9.7E−04 3R4F + SBA15 (8%) 0.00E+00 0.0E+00 0.0E+00

TABLE 8 Generation (mg compound/cigarette) of different toxic compoundspresent in the non-condensable products retained in the Tedlar bag whensmoking tobacco under controlled conditions Propional Acetal- Sample CO₂CO dehyde Toluene Benzene dehyde 3R4F 40.63 11.220 0.0208 0.0178 0.08490.3061 3R4F + 29.85 10.89 0.0152 0.0135 0.0655 0.2908 SBA15 (4%) 3R4F +24.27 7.59 0.0144 0.0088 0.0486 0.2125 SBA15 (6%) 3R4F + 22.53 6.500.0101 0.0068 0.0356 0.1446 SBA15 (8%) Sample Nicotine BenzaldehydePhenol p-Cresol 3R4F 0.593 2.9E−04 4.2E−03 5.6E−03 3R4F + SBA15 0.3591.1E−04 2.0E−04 9.9E−04 (4%) 3R4F + SBA15 0.233 5.7E−05 0.0E+00 3.8E−04(6%) 3R4F + SBA15 0.101 9.8E−05 0.0E+00 0.0E+00 (8%)

From this point of view, it must be pointed out as being particularlyinteresting the use of SBA-15 with a nominal concentration of 8% whichcaused the following reductions: 42% of CO, 90% of TPM, 51% ofpropionaldehyde, 62% of toluene, 58% of benzene, 53% of acetaldehyde,83% of nicotine, 66% of benzaldehyde, and practical disappearance ofother compounds.

1. Use of aluminosilicate SAB-15, or the acidic or sodium forms thereof,interchanged with Fe, Na, K, Ca, Ce, Zr, the oxides of Fe, Na, K, Ca,Ce, Zr and mixtures thereof as an additive for reducing the toxic andcarcinogenic substances present in tobacco smoke.
 2. Use according toclaim 1, where the aluminosilicate SAB-15 has a spherical morphologicalshape, tubular morphological shape or rod shape.
 3. Use according toclaim 1, where the aluminosilicate SAB-15 has a pore size comprisedbetween 4-10 nm and a mesopore volume preferably greater than 2.2 cm³/g.4. Mixture comprising dry tobacco and aluminosilicate SAB-15, or theacidic or sodium forms thereof, interchanged with Fe, Na, K, Ca, Ce, Zr,the oxides of Fe, Na, K, Ca, Ce, Zr and mixtures thereof as an additiveand not containing adhesive agents.
 5. Mixture according to claim 4,characterized in that the additive is at a concentration comprisedbetween 0.5-10% by weight with respect to the dry tobacco.
 6. Mixtureaccording to claim 5, characterized in that the additive is at aconcentration comprised between 2-7% by weight with respect to the drytobacco.